Many industrial automation systems include safety-rated devices with integrated safety subsystems that prevent or disable certain potentially unsafe device operations until a set of defined safe conditions are satisfied. For example, safety-rated motor drives (e.g., variable frequency drives, servo drives, etc.) are often configured to prevent the drive from turning a motor until the drive's safety features are properly configured and all defined safety conditions are satisfied. In the case of stand-alone drives (drives that operate independently of an external controller), this means that the user cannot instruct the drive to turn its associated motor—even in a pre-installation testing scenario—until the drive's safety configuration is defined and the safety input devices connected to the drive's safety inputs are confirmed to be in their respective safe states. In the case of networked safety drives (drives that operate under supervision of a safety controller that communicates with the drive over a network), the drive is prevented from turning a motor until the drive is connected to a properly configured safety controller and fully integrated into the larger safety system. Other safety-related devices, including but not limited to stand-alone and networked servos, enforce similar restrictions on certain operations until the device has been configured with a proper safety configuration.
During start-up or testing of an industrial system that includes such safety-rated devices, system designers often have need to execute a restricted operation—e.g., test run a motor to be controlled via a safety-rated motor drive—before the safety configuration is in place. This especially problematic in the case of networked safety devices, since the device must be networked to a configured safety controller before these restricted operations will be permitted. This creates an additional hardship during testing and installation, since the system designers may wish to perform these operations well before the rest of the safety system is in place.
The availability of both standard and safety-rated drives (and other devices) can also render inventory management more difficult. For example, a plant facility that utilizes both standard and safety-rated drives in their industrial systems must maintain both types of drives in inventory for replacement purposes.
The above-described deficiencies of today's industrial safety devices are merely intended to provide an overview of some of the problems of conventional systems, and are not intended to be exhaustive. Other problems with conventional systems and corresponding benefits of the various non-limiting embodiments described herein may become further apparent upon review of the following description.